Jay Leno and His Doble Steam Cars

Doble's innovative steam cars never go out of style.

One of my heroes was a guy named Abner Doble, an engineering genius and a perfectionist, who built his first steam car when he was in high school. Later, as an MIT student in 1911, Abner built a steamer with a condenser that turned vapor into reusable water; not even the Stanley Steamer had that range-extending feature.

Some years later, Abner, with assistance from his three brothers, founded the Doble Steam Motors Corporation. But he was a much better engineer than businessman; his outfit built just 36 cars from 1922 to 1931. I own two of them, both 1925 Model Es. One is a sedan, chassis No. 18. The other car, a roadster with chassis No. 20, was once owned by Howard Hughes. My Dobles are only two cars apart, but they are vastly different because Abner constantly tinkered with the car's design and mechanics. They say this incessant re-engineering meant that each model cost over $55,000 to develop. At a time when a Model T sold for $260, the Doble cost about $20,000, which would be roughly­ $250,000 today. And that was a big problem, even for what was, by 1925, the best steam car on the road. Plus, Abner was doggedly pursuing steam propulsion when all signs pointed to the internal combustion engine as the powerplant of the future. He was, in effect, perfecting the VHS tape when DVDs had just been released.

Abner could indulge himself because money wasn't initially an issue. His grandfather made a fortune selling tools to gold miners and his father perfected a power-generating water turbine. Financial troubles, however, eventually dogged the company. The brothers bickered and sued each other. Abner was convicted and then acquitted on appeal in a stock manipulation scandal. I think he was a lot like Preston Tucker. He sincerely wanted to build a good car, but some of his practices were questionable.

At least Doble's customers got an incredibly sophisticated automobile for their money. Superheated steam from a 1200-psi front-mounted boiler drives a four-cylinder double-­compound engine, which in turn powers the rear axle via a set of spur gears. The engine's high- and low-pressure cylinders reuse steam as it goes between the cylinder pairs, maxi­mizing efficiency. There are also complex water and oil pumps, a powerful 1-kilowatt electrical system to run the ¾-hp blower, pumps, lights and ignition, and a number of quartz rods that automatically regulate the steam temperature.

Unlike a Stanley, where you need a match or some other flame to fire up the boiler, the Doble self-ignites. The starting process begins by turning the key and pulling up the floor-mounted water-pump knob. There's a ticktickticktick from the water pump as it pressurizes the coils and pushes out air bubbles, generating 300 to 500 psi in seconds. Push the water-pump knob back down, turn on the ignition: zzzzoooouuuuu! Now you have fire, which can be fed by a variety of fuels, usually kerosene. Tubes coiled inside the firebox hold about a gallon of water and provide a lot of surface area for quick heat transfer. That, combined with about 2 million Btu of heat, quickly builds up steam, and you can pull away within a minute.

Since the crankshaft drives the rear wheels, there's no transmission and therefore no shifting. Open the hand throttle and acceleration from a dead stop is smooth and continuous. The Doble just continues to pull all the way. It only has about 150 hp, but the torque output is huge: 2200 lb-ft at the rear wheels. If you're on a hill, you just keep your finger on the throttle lever and it holds the car right there. Once it's up and cooking, the fuel is burned almost completely, like a propane torch, so when it's running, visible emissions are minimal. Care and maintenance are very labor-intensive, but as the owner's manual states, "Your man can do that."

My roadster came from the Nethercutt Collection in Sylmar, Calif. The late J.B. Nethercutt paid 10 guys for two years to restore it to exactly what Abner intended. I'd had my eye on it for 20 years. Dobles are like any other rare artwork. You say you're interested, and decades go by. And you either get a phone call or you don't.

Hughes's old car came very complete, so there have been just a few fittings to replace. Dobles have to be surgically clean and airtight to eliminate power losses through leaks; they need to hold a vacuum so the water returns to the boiler when everything cools down. I've driven this car more miles than it's been driven in many years, and it pulls away faster than you'd ever think possible in an 85-year-old car. But its steering is slow and heavy. We're trying different lubricants, and we think the steering box will loosen up. And like most cars of its era, it didn't come with front brakes. I call the Doble's binders the antistop brakes: They slow the car a little, but since there's no engine braking, they're scary. I'm going to install front brakes.

The smoothness and force of the acceleration, however, never fail to amaze me—it's like the Hand of God pushing you along. I was running at 85 mph the other day, and there was more to go. It's dead silent on the road, just wooooooooshhhhhh!!! Back in the day, Hughes was clocked at 132.5 mph on a Texas highway, faster than anything with an internal combustion engine. It proves what I've always believed: The last days of an old technology are almost always better than the first days of a new technology.

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